Controlling mechanism for drying tumblers



Dec. 23, 1930. E. J. CARROLL CONTROLLING MECHANISM FOR DRYING TUIIBLERS Fil ed Jan. 12, 1925 5 Sheets-Sheet 1 INVENTOR Dec. 23, 1930 E. J. CARROLL. 1,786,191

CONTROLLING MECHANISM FOR DRYING 'IUHBLERS 1930. E. J. CARROLL 1,786,191

CONTROLLING MECHANISM FOR DRYING TUIBLERS Filed Jan. 12, 1925 3 Sheets-Sheet 2 A TTORNE Y8 Patented use. 23, 1930 (UNITED-STATES PATENT "oer-loaf nuILflJ. caanonn, or ciucmna'rr, onro. Assmnon To run nrcnr IAUN'DBY IA err-many comrany, or nonwoon, 01:10, A conro no]! or onto CONTROLLING mncnnmsm FOB name mamas.

Application filed Jenner- 12, 1925.. Serial ll'o. 1,815.

This invention relates to improvements in drying apparatus for use in laundries or dry cleanin establishments, and to the control mechanism therefor.

One object of the present invention is to provide improved drying apparatus in which the materials to be. dried, such as clothing, fabrics or the like, are first subjected to a flow of heated air to remove the moisture or cleaning fluids therefrom, and are then subjected to a cold air current to cool and deodorize them. a

A further object of the invention is to prov vide improved control mechanism which is automatic in operation so that after the operthen automatically subject the-materials to. a

flow of cold air to cool and deodorize-them,

and to provide a suitable signal system for" advisingthe operator about the various ma: chine operations.

tail hereinafter. I

In the drawings, Fig. 1 is an end elevation of a drying tumbler embodying my invention, parts being broken away to show inter ior construction; Fig. 2 is a front elevation of a control unit, the casing cover being omitted Fig. 3 is a detail sectional elevation thereof on the line 3-3, Fig. 2; Fig. 4 is a similar 2; Fig. 5 is a detail section through a thenmostatic member, on the line 5-5, Fig. 1;] and 'Fig. 6 is a diagram of the electric cir-, cuits.

While the present invention may be ap-&

- Further objects'ofthe invention are part obvious and in part will appear more in de- View on a reduced scale, on the line 41- 4, Fig:

plied to many different es of apparatus or d 'ng purposes, the awings show it applie to a drying tumbler foruse in laun-' dries or ,dry c eamng--plants. The niecha nism and arran ment of the drying tumbler, from the stan point-of its mechanical manipulation of the material being-treated, is largely immaterial. For pu oses of illus-' tration the drawings show a d rying tumbler including a suitable hollow frame or "casing 1 provided with a drying chamber 2, a screen chamber 3, a fan chamber 4 and a' heating chamber 5. In the heating chamber are the usual steam heating coils or pipes 6 adapted to heat the air circulated over them and delivered through a passage 7 and opening 8 into the top of the drying chamber in'w'hi'ch I rotates the usual foraminous drum 9 containing the material to be treated, and which is rotated, usually reversely in opposite directions, by'suitable means, such as the .motor 10, Figs.- 1 and 6. The drying chamber com-- municates through an opemng 11 with the screen chamber 3 in which are .oneor more removable screens 12 adapted to collect lint and other foreign matter deposited upon" them. The machine is also provided with an air inlet, shown as a screened opening 13 through which atmospheric air may beintroduced to the air circulation'system, and asshown this opening communicates with the screen chamber below the screens therein. From the screen chamber the air flows to the suction side" of one or more suitable fans 01" blowers- 14 in the fan chamber, which dis-' charge the air delivered to'then'r from the screen chamber, either through anopening 1'5 into the bottom of the heat ng chamber, or through an o ning 16 into a passage 17 leadingtgau out et opening 18 to the atmosphere. course ofcirculation of air through the machine is controlled by suitable dampers 61;; valves, of which there are three in the particular machine shown, to wit dampers 1?, 20 and 21, each of which has two posi- 0.

tions. Damper 19 in its first position, shown in Fig. 1, closes the mouth 22, of a passage communicating either directly with the outer atmosphererfor example, beyond the wall of the building, or with a suitable source of cold air,'and through which cold or atmospheric air may, therefore, be introduced to the passage 7 just above the inlet 8 to the drying chamber, and in its second position uncovers the opening 22 and closes the passage 7, shutting off communication from the heating to the drying chamber.

Damper 20 in its first position, shown in Fig. 1, exposes the air inlet 13 to the screen chamber, so that a limited quantity of atmospheric air is permitted to flow into the screen chamber and to be discharged through the outlet 18 by way of a restricted passage 23 which leads from the periphery of the fan casing to the outlet passage 17 and hence will discharge the heavier strata of air circulated by the fan and which thus contain the larger proportion of moisture, and in its second position closes the air inlet 13.

Damper 21 in its first position shown in Fig. 1, closes the closing 16 to passage 17 leading to the outlet 18, affording free communication from the fan chamber to the,

heating chamber through opening 15, and in its second position closes opening 15 and opens the opening 16.

As a result of the foregoing arrangement there are two possible air circulation or conduction channels through the machine, the first for the heated air and the second for the cold or atmospheric air. \Vhen all dampers are in their first positions mentioned above, the fan or fans 14 discharge the air delivered to them largely through the opening 15 into the heater, such air flowing through the opening 8 into and through the drying chamber, thence through the screen chamber and back to the fan, but a limited quantity of atmospheric air is permitted to continuously enter the circulation channel through the inlet 13, while a corresponding limited quantity of air heavily laden with moisture is continually discharged through the passage 23 and outlet 18. When all dampers are in their second positions above mentioned, communication from the fan to the heating chamber is entirely cut off, air inlet 13 is closed and cold air inlet 22 is open, so that a relatively large quantity of cold or atmospheric air enters the passage 7 at the top of the machine, flows directly through the drying chamber and screen chamber to the fans from which it is discharged from the machine by way of opening 16, passage 17 and outlet 18, all for the purpose of aeration or freshening and also cooling the work.

The several dampers are controlled by suitable mechanism which in the machine illustrated in the drawings is constructed and arranged as follows:

All of the dampers are actuated simultaneousl by a manually operatable lever 25 norma ly held in one position by a tensile spring 25 and movable against the influence ofsaid spring to a second position. shown in Fig. 1. Said lever is pivoted at 25 on the casing and intermediate its ends is connected by a link 26 to an arm 27 on a shaft 28 to which damper 20 is attached. Said lever 25 is likewise connected by a link 29 to an arm30 on a shaft 31 to which the damper 19 is attached. The damper 21 is also actuated by lever 25, but in this case indirectly through the shaft 28, which is provided with a second arm 32 connected by a link 33 to one arm of a bell crank lever 34, the other arm of which is connected by a link 35 to an arm 36 upon the shaft 37 'to which damper 21 is attached.

The lower position of lever 25, shown in Fig. 1 of the drawings, is the hot air position, in which lever 25 may be held or latched against the action of spring 25 by any suitable releasable and readil controllable latching means. The means s own in Figs. 2 and 4 for this purpose comprises a latch 38 attached to a shaft 39 and bifurcated at its outer end to form a short arm 40 and a long arm 41 separated by a recess adapted to receive a lateral tongue 42 at the upper end of an arm 43 of the lever 25. When lever 25 is unlatched and raised to the cold air position the latch 38 occupies the dotted line position, Fig. 4. When lever 25 is depressed manually the lateral projection 42 thereon passes the arm 40, engages arm 41 and enters the recess between said arms and moves the latch 38 against the action of spring 44 to the position shown in full lines Fig. 4. Suitable means is provided to hold the latch in the position shown in full lines, the means shown for the purpose being a member 45, also fastened to shaft 39 and provided with a stopping abutment 46 and a latching shoulder 47 adapted to cooperate with a pin or roller 48 on an arm 49 carried by a shaft 50 to which is attached the armature 51 of an electro-magnet having a coil 52. Pin or roller 48 is caused to enter the notch above the shoulder 47 by a spring 53, but may be moved out of said notch and out of engagement with shoulder 47 either by energization of coil 52 to attract armature 51 or by manipulation of the exposed thumb piece 54 of a hand lever 54 pivoted at 55 and having a lower arm lying in front of the armature 51. With the parts in the position shown in full lines, Fig. 4, where lever 25 is latched in its lowest or hot air position, said lever may be unlatched or released to be moved to the cold air position either by energization of coil 52 or by manual operation of lever 54*. In the present construction the shift from hot air to cold air circulation conditions is controlled thermostatically and is accomplished automatically by means now to be described.

'gized, by a spring 61.

stationary contact 60, said switch being normally held open, when the coil 58. is deener- On said insulating base are also mounted a plurality, shown, of yieldingcontact fingers, marked respectively 62, 63, 64, 65 and 66 located and arranged to cooperate with bridging contacts carried and actuated by shaft 39. As shown,

. contacts 65 and 66 may be bridged to complete a circuit through them by a bridging contact 67. I Contacts 62, 63 and 64 cooperate with a bridging contact 68 having a fairly long center portion on which contact 63 rides and which is so long that contact is made between 63 and 68 in both positions of shaft 39,

' tween and 66 is open, all

I the shaft 39 and having two other contact portions 69 and 7 0 spaced or separated circumferentially of so that the bridging contact 68 acts like a single pole, double throw switch, completing a circuit connection between 62 and 63 when the circuit is completed between 65 and 66 and completing a circuit between 63 and 64 when the circuit connection befor purposes which .will appear. I

71 indicates a suitable thermometer .or thermostatic device mounted upon the casing and extending into the screen chamber fairly close to the opening from the drying chamber thereto and consequently sensitive to the temperature of the air issuing from the drying chamber. Said thermostatic element 71 is of ordinary form and is provided with a connection 72 to a suitable controller indicated generally at 73 and provided with a member 73" moved according to variations in temperature of 71 and with three electrical terminals 74, 75 and 76. The movable member 7 3 of the controller is adapted when the temperature at the member 71 reaches a between the center terminal 75 and the maximaximum to, complete electrical connection mum temperature contact 76" connected to terminal 76 and when the temperature at member 71 is at a minimum to similarly coinplete the connection between the terminals adjustable, such as by adjustment of the con tacts 7.6, 7 4*,indicated in dotted lines, Fig. 6, to enable the maximum and minimum temperatures at which circuit connections will be thus completed to be varied, enabling the device to be set-to respond to any desired range between maximum and minimum tempera;

tures.

77 and 78 represent respectively two indicators, such as electric lamps, of which lamp 77 serves to indicate the circulation of cold air while 78 indicates the circulation of hot air.

79 is a normally closed yielding stop button and 80a normally open yielding start and that a. heating agent, such as steam, is

flowing through the coils 6,'and that the cylinder door, not shown, and the outer casing door 83 are closed. The first operation in starting is to set into operation the fan driving motor, which through suitable mechanism, indicated conventionally at 84, drives the controller for the cylinder reversing motor 10, said controller being illustrated at 85 as of-the conventional continuously rotating drum type, to be referred to more in detail hereafter.

The fan driving motor 86 is started by depressing normally open start button 87, closing a circuit through the coil 88 of the starting relay, thereby closing the switches 89 and 90. Closing of switch 89 completes a circuit from positive through coil88, normally closed stop button 91, shunt winding 92,

switch 89 to negative. Closing of switch 90 around the coils 95, 96 and 97 and throws the motor directly across the line. Controller drum 85 is therefore now continuously driven in the direction ofthe arrow 99, Fig. 6.

The next operation is to start the cylinder reversing motor 10, which is accomplished by momentarily depressing the normally open start button 80, thereby completing a circuit from positive through the coil 100 of the starting relay, normally closed stop button 7 9, start button 80 to negative. Energization of coil 100 closes the switches 101,102, of which switch 101 completes the maintaining circuit for coil 100, said circuit being through coil 100, stop button 79, shunt winding 103' of the lock out switch 104, contacts 101 to negative; Switch 102 completes the initial starting circuit for motor 10 through controller 85 which operates as follows:

Said controller is provided with two series of segments, of whi 1 segments 105, 106, 107,

108, 109, 110 and 111 may be assumed to be for producing left hand rotation of the cylinder 9 and segments 112, 113, 114, 115, 116,

117, and 118 are for producing right hand rotation of the cylinder. Said segments cooperate with a series of properly located and arranged spring fingers numbered respectively 119 to 127. Segments 105, 106, 112 and 113 of the controller are connected by the common bridge 128, While all remaining segments of the controller are connected by the common bridge 129. Spring contacts 121 and 123 are connected by the bridge 130, while contacts 120 and 124 are connected by the bridge 131. In circuit to the several contacts are a series of starting resistances numbered respectively 132, 133, 134 and 135.

Let us assume that switch 102 has been closed, as before stated, and that the left hand segments in Fig. 6 first make contact with the contacts 119, 120, 122 and 123. The first effect is to complete a circuit from 119 to 105 and from 122 to 107 so that current flows from positive by way of the series winding 136 of the lock out switch, resistance 132, contact 122, segment 107, segment 108, contact 123, bridge 130, contact 121, the armature of motor 10, contact 120, segment 106, segment 105, contact 119 and switch 102 to negative. The field circuit of motor 10 from positive, through the field and switch 102 to negative, is obvious. In a shorttime, segment 109 engages contact 125, so that resistance 134 is inserted in parallel with resistance 132 for the second step of resistance. During either the first or second step of resistance the shunt winding 103 of lock out of switch 104 preponderates over the series winding 136, thereby closing the contact 137 and inserting resistance 133 in parallel with resistance 132 or resistances 132 and 134, as the case may be. Next, segment 110 engages contact 126 and inserts resistance 135 in parallel, while final segment 111 engages contact 127 and shortcircuits all resistance, throwing the motor across the line. The drum continues to rotate in the forward direction until the forward segments 105, 106, 107, 108 and 111 simultaneously leave their respective contacts. The motor 10 then coasts until thereverse segments 112 to 118 in turn engage the contacts 119 to 127, thereby reversing the direction of flow of current through the armature of motor 10 and inserting resistance in parallel by steps to produce successive decrements of effective resistance for the starting operation. Motor 10 therefore drives the cylinder 9 continuously, but first in one direction and then in the other direction until its operation is interrupted by means later to i be described.

r ers has been first shifted to the position shown in Fig. 1 to be latched by the latch 38, as indicated in full lines, Fig. 4. As before stated, said latch is controlled thermostatically. As soon as switch 102 is closed the circuit through the thermostatic controlling mechanism. indicated generally at 138, is completed by Way of Wire 139 to the negative end of the field winding of motor 10. Under this condition, hand switch 140 for the therniostatic system being closed, a circuit is com pleted through the bridge 70 and hot air indicating lamp 78; the illumination of which indicates that the machine is running with a hot air circulation. All other circuits are open, but a circuit is completed by way of wire 141 to the center contact 75 of the thermostatic controller. When the temperature of the air affecting the thermostatic element 71 reaches the desired or predetermined maximum the movable member 73 of controller 73 completes a circuit across the contacts 75, 76, thereby completing a circuit through the coil 58 and closing the switch 59, which completes a circuit through the coil 52 of the latch mechanism. Energization of this coil attracts the armature 51 and releases member 45 enabling the spring to lift the control lever 25 in Fig. 1 and move all three dampers to the cold air position. Latch 38 and its holding latch are moved by the spring 44 to the dotted line position,

Fig. 4. The effect of rotation of shaft 39 by spring 44 is to move the bridges 69, 70 and 67 to their second positions, closing the circuit across 62 and 63. closing the circuit across 65 and 66 and opening the circuit across 63 and 64. The lamp 78 therefore goes out, while lamp 77 indicating the circulation of cold air is illuminated. At the same time a circuit to negative through wire 142, including the audible signal 81 and the door operated switch 82, is completed to contact 74, said circuit being effective to be completed by the thermostatic controller 73 in due course. As the cold air circulated through the machine lowers the temperature at the thermostatic element 71, the movable member 73 of the controller 73 moves away from its former position, first opening a circuit across 75, 76 and de-energizing coil 58, allowing switch 59 to be opened by its spring 61 and thereby de-energizing coil 52 preparatory to re-setting of the latching mechanism. Finally, when the temperature of the circulating air at the thermostatic element 71 has been lowered to the desired or predetermined temperature, the movable member 73 of the thermostatic controller 73 completes a circuit across 74, 75, thereby completing the circuit through the audible signal 81, which sounds the necessary alarm, and through the door operated switch 82. Hearing the alarm the attendant goes to the machine and first operates the stop button 79, thereby opening the circuit through the maintaining coil 103 of the lock out switch 104 and through the coil 100, so that switches 101, 102 and 137 are opened, bringing the cylinder reversing motor 10 to rest. He then opens the outer door 83 of the casing, enabling the switch 82 to be opened by its spring and opening the' circuit through the audible signal 81. The door of the'cylinder -9 is then opened, the finished work-therein removed and the machine lfoaded with another batch of material to be dried.

Proceeding now in the regular order the attendant pulls down the operating handle 25 to re-set the several dampers and closes the doors of the cylinder and casing, then starting the cylinder reversing motor by momentarily depressing the start button 80, as before. However, if the operator neglects to.

pull down the operating handle 25 before closing the outer casing door the switch 67 'remains in circuit closing position, completing the circuit through the audible signal 81 which therefore sounds an alarm as soon as the door is closed and warns the operator that he has failed to pull down the controlling handle 25. Retracing his steps is not necessary, but the operator can immediately correct the omission by pulling down the handle 25' and re-setting .the dampers to their original position and moving the bridges 69, 7 0 and 67 to the position shown in Fig. 6, which not only opens the alarm circuit but also causes the machine to perform its regular cycle of operations, before described. 1

This machine very materially reduces the labor and attention necessary in the drying of clothes in laundries or dry cleaning establishments, chiefly due to the automatic control of the air circulation system, a control which is possible, because experience has shown that the clothes will be properly dried according to the requirements in such establishments if raised to a given maximum temperature and then cooled to a definite predetermined minimum temperature. This fact enables automatic mechanism to be employed, subject to its control by thermostatic means and enabling the attendant to set the machine in operation with the knowledge that when the'proper drying operation has been accomplished, and not before, he can return to themachine and re-load it, leaving his time ifithe interval availablef or other duties. Moreover, the clothing or other materials in the machine is not only dried, but is quickly brought to a desired normally relatively low temperature so that they can be immediately removed from the cylinderina cool condition suitable for handling. There is no necessity of periodically stopping the machine to test the materials to determine whether or not they'are sufficiently dry, nor is there any 1 danger of drying materials for too long a time either with deleterious efiect upon the fabric or of drying too far starch contained in the materials to be ironed. .Nei'ther are the materials subjected to excessive tumbling or agitation and thereby either physically harmed or so beaten that the starch is pounded out. 7

V In thesystem so far described, the effect of movement of the movable member 7 3 of the thermostatic controller to the minimum temperature position is to energize the audible signal 81 and sound an alarm, leaving it to the operator to attend and stop the machine. However, if desired, the machine may be so arranged that when temperature 1s reached, not only is the alarm sounded, but also either the cylinder rotating'motor 10 or the fan rotating motor 86 or both, may be automatically stopped. For example, the drawings show two circuits 143, 144 in paral-' lel with the circuit 142 through the signal 81 and energized simultaneously therewith by the thermostatic controller 73. Circuit 143 may be rendered efiective whenever desired by its manuallyw controlled switch 145 and is effective when energized to stop the. cylinderl rotating motor 10, for which purpose saidl circuit includes an electro-magnet, the coil 146 of which opens a normallyclosed switch 147 in the maintaining circuit for the first relay coil 100. Circuit 144 may be rendered effective when desired by closing its switch 148 and when energized stops the fan rotating motor, for which purpose said circuit includes an electro-mag'net, the coil 149 of which opens a normally closed switch in the maintaining circuit for the coil 88 .of the relay controllin the fan motor. Circuit 143 may be connecte' to negative through the switch 101 of its corresponding motor controlling relay, while circuit 144 may be connected to negative through the switch 89 of its relay. Consequently when either of said circuits has been energized by action of the thermostatic controller 73 itde-energizes its corresponding relay to stop its motor and in turn is de-en-' ergized by the relay action so that the parts are restored to initial position. However, when either of the motors 10 or 86 has been stopped by operation of the relay coil 146 or 149 as the case may be, such motor cannot again be started until the operating handle 25 has been depressed to re-set the dampers to their original positions and thus move the bridge 67 away from contacts 65; 66. If handle 25 has not been depressed, an attempt to start either of said motors by pressing its proper start button will immediately energize the relay coil 146 or 149 and 0 en the motor circuit attempted to be close This is an additional safeguard when desired. 125

While, of course, the control of he latching mechanism and thereby of the dampers in the present apparatus is effected by a thermostatic element sensitive to variations in temperature, nevertheless, in a way the air circulation is controlled by or in accordance with the humidity of the heated air. In other words, the humidity of the heated air has an efiect upon the temperature to which the thermostatic element is sensitive and by setting the thermostatic element to a desired maximum temperature responsive point, practically any desired predetermined minimum degree of humidit may be reached in the drying operation. or example, in wet wash plants the goods are tumbled in a drying tumbler, such as the one here described, not only to break up the mass, but also to remove a portion of the water. WVith the present apparatus, the maximum temperature setting may be reduced so that when the hot air is cut off there will remain in the material a predetermined percentage of moisture which may be greater than the percentage of moisture in clothes dried for other subsequent laundry operations.

Again, in drying Woolen materials a lower temperature is desirable than for other materials to prevent injury to the wool. Control of the temperature may be effected in different ways. For example, in Fig. 1, the damper 19 is adjustable relatively to its operating link 29 and therefore relatively to the other dampers, such as by providing member 30 with a slot 30 at various points along which may be adjustably fixed the pivot pin 29 connecting members 29 and-30. Damper 19 may thereby be adjusted during the drying operation so as to admit cold air in small quantity to the circulating air current to reduce its temperature to such a degree that it will not injure the material and will still be hot enough to liberate the moisture from the same.

The temperature for drying woolens may also be taken care of by the use of a thermostatic element 160, Fig. 1, having a portion in or sensitive to the air current leaving the heating chamber and which thermostatic element, as shown in Fig. 6, actuates a suitable switch, not shown, in a circuit 161 including a coil 162 for actuating and when energized for opening the normally closed valve 163 in the steam supply line for the coils 6. Thermostatic element 160 may be of any suitable form, preferably adjustable and so arranged that if the temperature of the heater drops below a givenvalue the circuit 161 is closed and steam is turned on, while if the temperature of the heater rises above said value, the circuit 161 is opened and valve 163 closes and shuts off the steam. Obviously, when such an arrangement is used the thermostatic element 160 can be set to respond at a temperature greater than the maximum temperature at which the thermostatic element. 7 3 is operated.

With this arrangement the operator is Warned by the audible signal of termination of the drying operation, but need not hasten to the machine to stop either its fan or rotating cylinder, which are automatically stopped by the mechanism. Excessive beating of the clothes or over-running is therefore avoided when the operator is in any way delayed in attending the machine. Operation of the fan in some cases is preferably automatically terminated, as described, but such termination is not important because additional cooling effect will not harm the clothes and the cold air circulation may be continued while the machine is unloaded and re-loaded. However, in some cases automatic stopping of the fan motor is desirable, when for ex ample, additional operation thereof beyond thenormal period might restore some mois ture from the atmosphere to Work already properly dried.

Other advantages will be apparent to those skilled in the artto which it relates.

What I claim is:

1. Apparatus of the character described comprising a chamber for the material to be treated, shiftable means enabling first hot air and then cold air to be passed over the material to be treated, and means sensitive to the temperature of said air current for first shifting said means at one temperature and producing a signal at another temperature of the air -current.

2. Apparatus of the character described, comprising a treating chamber, means for agitating 'therein the material to be treated, means for circulating air therethrough, and means sensitive to the temperature of said air current for controlling the operation of said agitating means and adapted whensaid temperature reaches a predetermined maximum to vary the character of the air current and when said temperature reaches a predetermined minimum to stop said agitating means.

3. Apparatus of the character described, comprising a treating chamber, means for agitating therein the material to be treated, shiftable means enabling either heated or cold air to be circulated through said chamber, and means controlled by the temperature of said air current for automatically shifting said 'shiftable means when the temperature of said current reaches a predetermined maximum.

4. Apparatus of the character described, comprising a treating chamber, means for agitating therein the material to be treated, shiftable means enabling either heated or cold air to be circulated through said chamber, and meanscontrolled by the temperature of said air current for automatically shifting said shiftable means when the temperature of said current reaches a predetermined maximum and for stopping said air current when the temperature reaches a predetermined minimum.

5. Apparatus of the character described, comprising a treating chamber, means for agitating therein-the material to be treated, shiftable means enabling either heated .or

cold air to'be circulated through said chamher, and means controlled by the temperature ofrsaidiair currentl'for automatically shifting said shi'fiab'le means when the temperature ofsa-id current'reaches a .predetermined'maximined mimmum.

mum-and for stopping said agitating means when'thertemperature. reaches a predeter- 6; Apparatus-of the character described,

comprising a-treating chamber, means for agitatin'g therein the material to be treated, shiftable .meansenabling either heated or cold air to becirculatedthrough said chamber, and means controlled by the temperature of said air current for automatically shifting saidshiftable means when the temperature of said currentreaches-a predetermined maximum and for stopping said air current and said agitating means when the temperature reaches a predetermined mini- 9. matically actuating said controlling means to cut ofi communication between saidair chammum. v

7. Apparatus of the character described, comprising a treatingchamber, a source of heated air adapted for communication with said,chamber, a source of cool air adapted for communication with said chamber, means for controlling communication between said air sources and said chamber, and means for autoher and said source of heated 'air when the temperature of the air in said chamber reaches a predetermined high point which 3 denotes the desired heated air treatment of the material in said chamber, for automatically' establishing communcation between said chamber and said source ofcool air, and for automatically cutting olf communication between said chamber and said sourceof cool the character thereof at one temperature and for stopping said air flow at another tempera- 'ture.

9. Apparatus of-the character described, comprising a chamber for material to be treated, meansjfor effecting a flow of air through said chamber, and means sensitive to the temperature of said air flow for varying other temperature.

the thermal character thereof at one temperature and for stopping said air flow at an- 10, Apparatus of the character described, comprising a: chamber for material to be treated, means for efiecting a flowof air through said chamber, and means sensitive to the temperature of said air flow forvarying the character thereof at a predetermined air flow at a predetermined minimum temper: ature;

11.- Drying apparatus oi tha character demaximum temperature 'and'for stopping said scribed, comprising 'achamber for material to be dried, means for subjectin'g'material in said chamber to drying and coolin'gtreatments, automatically operable signal means for each ofsaid treatments adapted-to be op-- erated throughout the duration thereof, and

additional signal means adapted to be automatically'operated at the termination of said second treatment. e 1 12. Apparatus of the character described,

comprising a chamber for materialto be treated, means for agitating the. material in said chamber, means for eifecting a passage of air through said chamber, and means sensitive to the temperature of said air current for controlling the operation of said agitating means and adapted when said air current reaches one predetermined temperature to vary the character of said air current and when a second predetermined temperature is reached to stop said agitating means.

13. In a laundry drying mechanism, a clothes receptacle, an air inlet and an air outlet for said receptacle, means for supplying hot air to said inlet and means responsive to a predetermined difference in the temperatures of the air in the said inlet and said outlet for preventing said means first mentioned from supplying hot air to said inlet.

14. In a laundry drying mechanism, a clothes receptacle, an air inlet and an air outlet for said receptacle, means for supplying hot air to said inlet and means responsive to a predetermined change in the temperature of the air in the said outlet for preventing air from being supplied to the said inlet.

15. In a laundry drying machine, a drying mechanism including means for conducting hot air to the clothes being dried, means for conducting the usedair .from the said laundry and means responsive to a predeter 17. The method of drying laundry toa predetermined degree which comprises, placing the laundry in a closed container, con

ducting a stream of air into said container past said laundry and terminating the drying operation when the temperatures at, an inlet and an outlet air duct of said container reach a predetermined relation.

18. Themethod of dehydi'atinjg. which comprises, placing material to be dehydrated in a closed container, connecting said container to a source off-dehydrating air and terminating the dehydrating action when the temperature of the air reaching said container from said source prior to its contact With said material reaches a predetermined relation with respect to the temperature of said air after contact with said material.

In testimony whereof I hereby afiix my signature.

EMU; J. CARROLL. 

